Hair in its natural state is rather impervious to damage. However, due to environmental conditions as well as the abuse to which it is usually subjected, hair can wear out at abnormal rates, causing its natural shield--the cuticle--to fall out and the cortex to shatter ending in breakage. Hair treating compositions and conditioners in particular, are designed to attempt to prevent or restore this damage. State-of-the-art products achieve these goals with various degrees of success, but all fail at providing the benefit for prolonged periods of time, particularly, after shampooing previously treated hair.
A typical high quality hair conditioner is expected to provide benefits to the hair such as detangling and low comb drag, among others, without imparting an unnatural or greasy feel to the hair. The conditioning effect also should not interfere with setting of the hair, i.e., it should not diminish the hair's ability to retain curl or hair style. Further, a conditioner should not make the hair stringy or dull a few hours after application. The dulling effect of some conditioners can occur by wicking the natural oils from the scalp up the hair shaft or by attracting dirt.
Hair conditioners formulated with ingredients containing functional groups substantive to the hair such as quaternized proteins, quaternized amines, amine oxides or silicone polymers with amino functional groups tend to be substantive to the hair to varying degrees. Substantivity is the capacity of a substance to absorb/adsorb to a surface. In general, hair substantivity for conditioning ingredients increases with more hydrophobic character, higher molecular weight, and higher charge densities (with positively charged molecules).
Most of these ingredients provide acceptable conditioning benefits to varying degrees, but fail to provide a longer-lasting clean feeling while providing long lasting conditioning benefits. As a rule of thumb, it can be stated that the greater the substantivity of the conditioning ingredient, the greater the likelihood it will impart a greasy coated feel to the hair or more generally, an unnatural feel and appearance. With some ingredients, over-conditioning and build-up is the result. The build-up effect is manifested as the inability of the hair to hold a set and/or by having a matted stringy look. Heretofore the difficulty in developing products with residual action and good performance without debilitating negative effects, as described, has limited the ability of hair product formulators and marketers to provide a product the consumer does not have to use every time he or she uses shampoo.
It is therefore an object of this invention to provide methods for treating hair employing a composition containing a blend of two polysiloxane polymers whereby cross-linking of the polymers takes place on the hair.
It is a further object of this invention to provide hair-treating compositions which contain a low viscosity emulsion of a reactive hydroxy terminated dimethyl polysiloxane and a reactive methyl hydrogen polysiloxane, said polysiloxanes being unreacted in the composition.
It is a still further object of this invention to provide hair treating compositions and methods which provide good conditioning benefits for prolonged periods of time, particularly after repeated shampooing.
It is another object of this invention to provide a hair treating composition which is highly substantive to hair, and provides long lasting hair conditioning properties without build-up or over conditioning.